Should I be angry and freaked out? Or should I shut up? (please see details)

So I have written on here before that I am in a very rural area, taking care of my 88 year old father. We have finally arranged to bring him back to town, and my older sister, whom I love to bits. has taken care of all the logistics. She has come here with her husband, whom she has been married to for about five years. ( I am living with them back in town, if you can follow this). I don’t think her husband likes me, and never has. In town, I hide in my room or absent my self often. So, tonight, her husband went into the back of my father’s house, ( it’s a nine bedroom house) and returned with my flask of vodka in his hand. I am not a drunk and had it there for the entire month and half that I have been here. It was in the drawer of my bedside table. I was shocked and upset that of all the rooms he should enter that one, and look into a bed side drawer. I said, “what were you doing in my room?” and he replied that he did not know it was my room. Did he not see the pink socks on the floor, the jewelery that he would know is mine on top of the table, the open computer on the bed, the clothes that are mine strewn around the room? Is this weird? Or not? I don’t know what to think.